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        <p class='location'>Crate regex_syntax</p><div class="block items"><ul><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#functions">Functions</a></li><li><a href="#types">Type Definitions</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'regex_syntax', ty: 'mod', relpath: '../'};</script>
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<h1 class='fqn'><span class='in-band'>Crate <a class="mod" href=''>regex_syntax</a></span><span class='out-of-band'><span id='render-detail'>
                   <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">
                       [<span class='inner'>&#x2212;</span>]
                   </a>
               </span><a class='srclink' href='../src/regex_syntax/lib.rs.html#11-2043' title='goto source code'>[src]</a></span></h1>
<div class='docblock'><p>This crate provides a regular expression parser and an abstract syntax for
regular expressions. The abstract syntax is defined by the <code>Expr</code> type. The
concrete syntax is enumerated in the
<a href="../regex/index.html#syntax"><code>regex</code></a>
crate documentation.</p>

<p>Note that since this crate is first and foremost an implementation detail for
the <code>regex</code> crate, it may experience more frequent breaking changes. It is
exposed as a separate crate so that others may use it to do analysis on regular
expressions or even build their own matching engine.</p>

<h1 id='example-parsing-an-expression' class='section-header'><a href='#example-parsing-an-expression'>Example: parsing an expression</a></h1>
<p>Parsing a regular expression can be done with the <code>Expr::parse</code> function.</p>

<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">regex_syntax</span>::<span class="ident">Expr</span>;

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">Expr</span>::<span class="ident">parse</span>(<span class="string">r&quot;ab|yz&quot;</span>).<span class="ident">unwrap</span>(), <span class="ident">Expr</span>::<span class="ident">Alternate</span>(<span class="macro">vec</span><span class="macro">!</span>[
    <span class="ident">Expr</span>::<span class="ident">Literal</span> { <span class="ident">chars</span>: <span class="macro">vec</span><span class="macro">!</span>[<span class="string">&#39;a&#39;</span>, <span class="string">&#39;b&#39;</span>], <span class="ident">casei</span>: <span class="bool-val">false</span> },
    <span class="ident">Expr</span>::<span class="ident">Literal</span> { <span class="ident">chars</span>: <span class="macro">vec</span><span class="macro">!</span>[<span class="string">&#39;y&#39;</span>, <span class="string">&#39;z&#39;</span>], <span class="ident">casei</span>: <span class="bool-val">false</span> },
]));</pre>

<h1 id='example-inspecting-an-error' class='section-header'><a href='#example-inspecting-an-error'>Example: inspecting an error</a></h1>
<p>The parser in this crate provides very detailed error values. For example,
if an invalid character class range is given:</p>

<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">regex_syntax</span>::{<span class="ident">Expr</span>, <span class="ident">ErrorKind</span>};

<span class="kw">let</span> <span class="ident">err</span> <span class="op">=</span> <span class="ident">Expr</span>::<span class="ident">parse</span>(<span class="string">r&quot;[z-a]&quot;</span>).<span class="ident">unwrap_err</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">err</span>.<span class="ident">position</span>(), <span class="number">4</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">err</span>.<span class="ident">kind</span>(), <span class="kw-2">&amp;</span><span class="ident">ErrorKind</span>::<span class="ident">InvalidClassRange</span> {
    <span class="ident">start</span>: <span class="string">&#39;z&#39;</span>,
    <span class="ident">end</span>: <span class="string">&#39;a&#39;</span>,
});</pre>

<p>Or unbalanced parentheses:</p>

<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">regex_syntax</span>::{<span class="ident">Expr</span>, <span class="ident">ErrorKind</span>};

<span class="kw">let</span> <span class="ident">err</span> <span class="op">=</span> <span class="ident">Expr</span>::<span class="ident">parse</span>(<span class="string">r&quot;ab(cd&quot;</span>).<span class="ident">unwrap_err</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">err</span>.<span class="ident">position</span>(), <span class="number">2</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">err</span>.<span class="ident">kind</span>(), <span class="kw-2">&amp;</span><span class="ident">ErrorKind</span>::<span class="ident">UnclosedParen</span>);</pre>
</div><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.ByteClass.html"
                                  title='struct regex_syntax::ByteClass'>ByteClass</a></td>
                           <td class='docblock-short'>
                                <p>A byte class for byte ranges only.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.ByteRange.html"
                                  title='struct regex_syntax::ByteRange'>ByteRange</a></td>
                           <td class='docblock-short'>
                                <p>A single inclusive range in a byte class.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.CharClass.html"
                                  title='struct regex_syntax::CharClass'>CharClass</a></td>
                           <td class='docblock-short'>
                                <p>A character class.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.ClassRange.html"
                                  title='struct regex_syntax::ClassRange'>ClassRange</a></td>
                           <td class='docblock-short'>
                                <p>A single inclusive range in a character class.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Error.html"
                                  title='struct regex_syntax::Error'>Error</a></td>
                           <td class='docblock-short'>
                                <p>A parse error.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.ExprBuilder.html"
                                  title='struct regex_syntax::ExprBuilder'>ExprBuilder</a></td>
                           <td class='docblock-short'>
                                <p>A builder for configuring regular expression parsing.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Lit.html"
                                  title='struct regex_syntax::Lit'>Lit</a></td>
                           <td class='docblock-short'>
                                <p>A single member of a set of literals extracted from a regular expression.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Literals.html"
                                  title='struct regex_syntax::Literals'>Literals</a></td>
                           <td class='docblock-short'>
                                <p>A set of literal byte strings extracted from a regular expression.</p>
                           </td>
                       </tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="enum" href="enum.ErrorKind.html"
                                  title='enum regex_syntax::ErrorKind'>ErrorKind</a></td>
                           <td class='docblock-short'>
                                <p>The specific type of parse error that can occur.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="enum" href="enum.Expr.html"
                                  title='enum regex_syntax::Expr'>Expr</a></td>
                           <td class='docblock-short'>
                                <p>A regular expression abstract syntax tree.</p>
                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="enum" href="enum.Repeater.html"
                                  title='enum regex_syntax::Repeater'>Repeater</a></td>
                           <td class='docblock-short'>
                                <p>The type of a repeat operator expression.</p>
                           </td>
                       </tr></table><h2 id='functions' class='section-header'><a href="#functions">Functions</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="fn" href="fn.quote.html"
                                  title='fn regex_syntax::quote'>quote</a></td>
                           <td class='docblock-short'>
                                <p>Escapes all regular expression meta characters in <code>text</code>.</p>
                           </td>
                       </tr></table><h2 id='types' class='section-header'><a href="#types">Type Definitions</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="type" href="type.Result.html"
                                  title='type regex_syntax::Result'>Result</a></td>
                           <td class='docblock-short'>
                                <p>An alias for computations that can return a <code>Error</code>.</p>
                           </td>
                       </tr></table></section>
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